One of the great things about the Genesis (or Mega Drive, depending on where you're from) is the fact that, unlike most other major consoles, Sega licensed out its technology, meaning a range of companies could , along with Sega itself, come up with their own wacky versions of the console.

While some of these were disasters, some were surprisingly innovative pieces of technology.

The actual, official, standard Sega Genesis/Mega Drive was first released in Japan in 1988, and over the next nine years would see just one official worldwide update, the Genesis/Mega Drive II. Meaning as far as Sega was concerned, for the majority of consumers over the system's original lifespan, there were just two consoles.

For a select few, though, and depending on the region, there were many, many more. From 1988 until the present day, over a dozen variations and special models of the Genesis have been released, ranging in price and scope from cheap retro playthings to complicated, expensive computer systems.

The gallery above details some of our favourites, so click through to see them in all their strange, strange glory.

Total Recall is a look back at the history of video games through their characters, franchises, developers and trends.

Sega PAC - The Sega PAC was an add-on for the Pioneer LaserActive Laserdisc player, which literally bolted onto the media unit and allowed it to play both Genesis and Sega-CD games. Costing $600 upon release in 1993 (and that's just for the add-on), the Sega PAC was an expensive unit for a short-lived, expensive machine. It did, however, come with a fancy custom controller.

Wondermega - Sega licensed both its Genesis and Sega-CD technology to JVC, who released a variation on the console known as the Wondermega (or, for some Americans, the "X'eye:). While for all intents just a Genesis and Sega-CD in different casing, the Wondermega did ship with some cool music-creating tools, and these days looks a lot like something you'd see lying around the Mass Effect universe.

Mega Jet - In the early 1990's, Japan Airlines was at the forefront of pioneering in-flight entertainment, and was doing so with devices like the Mega Jet, a "portable" Mega Drive unit that users plugged into seat-back screens and that could play any retail cartridge from the console. The Mega Jet would (with the addition of a colour screen) later be released in the US as the Sega Nomad, a true portable Genesis console that could chew through an entire packet of AA batteries in the time it'd take you to get past a game's menu screen.

Amstrad Mega PC - Perhaps the most unusual of all, and certainly my personal favourite, the Amstrad Mega PC was a complete personal computer that also shipped with a Mega Drive console contained within. It was released in 1993 in Europe and Australia, and despite my ceaseless protestations, I was never allowed to get one. Probably because, as would ultimately doom the system, it was a rubbish PC by 1993 standards, with the addition of a Mega Drive (the console's board was simply slid into the computer's casing) not justifying the expensive cost for such a rubbish PC.

The Sega TeraDrive was a similar project for the Japanese market, only its PC was made by IBM, not Amstrad.

Sega Mega-Tech - The Mega-Tech was an arcade system developed by Sega which used Mega Drive hardware - complete with cartridge slots - for arcade gaming. Instead of buying credits, a player's money bought time on the system, the potentially shorter time offset by the ability to switch between whichever cartridges the machine had installed mid-game.

While never released in North America, the Mega-Tech (and its successor, the Mega-Play) played host to some of Sega's best games, like Outrun, After Burner, Shinobi, Golden Axe and Sonic.

Sega Multi-Mega - Oh dear. The Multi-Mega, known as the CDX in the US, was a 1994 release that hoped to make Mega Drive gaming look a little more sleek and modern by slimming it down in the casing of a discman, or portable CD player. A tiny device not much larger than its CD drive, the Multi-Mega could play Sega CD and Mega Drive games. Woefully expensive and utterly pointless, it was the last full-price Mega Drive console offered by Sega, and as such is a sad chapter to close out one of the best gaming consoles of all time.

Note that these are just some of the variations of the Genesis/Mega Drive released. Both Sega and other companies have put out a number of cheap, retro "re-releases" of the hardware, some dating as far back as the late 1990s (the Genesis 3) and others still being released "new" to this day.